As described in U.S. Pat. Nos. 7,866,380 and 7,959,814, one of the most pressing needs throughout the world is drinkable water. An untold number of humans die every year because the water they consume is contaminated. In some areas, people are forced to spend a great deal of time manually hauling water from a distant source to their homes and villages rather than taking the risk of drinking untested water that might be nearby.
There are many methods of purifying water. One of the most common is reverse osmosis (RO). This process has been around for a long time, but it has its drawbacks. Although RO systems can be inexpensive, there is an ongoing maintenance requirement of filter replacement. Filters in RO systems can become clogged and/or damaged by constant exposure to the water source being purified. Cost and availability of replacement filters and the skill level to perform this maintenance requirement can present a problem.
Another method of water purification includes adding chemicals to the water to kill pathogens. Generally, chemical applications are used for situations where small amounts of water need purification. Although effective when the proper concentrations of chemicals are used, it is difficult to always measure the proper amounts. In addition, this system of purification does not address problems with heavy metals that may be present in water.
Boiling water is another way of killing pathogens in water. Unfortunately, in many parts of the world where contaminated water is a major problem, the availability of materials to heat water, such as wood, does not exist.
In particular areas or industries, hot water and/or steam may be needed, but it may be critical that no open flames be used to heat the water. One such industry is the oil field service industry. In many geographical regions oil reservoirs are found to contain high concentrations of paraffin, a waxy crystalline hydrocarbon. This substance, while commercially useful in the manufacture of coatings, sealants, candles, rubber compounding, pharmaceuticals and cosmetics, can present a problem with regard to the production of oil. Paraffin suspended in the crude oil tends to clog perforations in the oil well's production string and slows the flow of crude oil to the surface.
Several technologies have been in use for many years to minimize the detrimental effects of paraffin. Among these is injecting hot water, steam or chemical solvents into the well to clean out the wells perforations by liquefying the paraffin either by heating it above its melting point or chemically changing its composition. While effective, all of these have their shortcomings.
When the hot water method is employed, water must be transported to the well site then heated in a LPG or diesel fired boiler mounted either on a truck chassis or trailer. Availability of water at the well site is a common problem, and unsafe conditions exist when an open flame, like those used to heat water or crude in the boiler tanks, is positioned near the wellhead where there may be a high concentration of natural gas in the atmosphere.
The steam method usually entails the building of a power plant utilizing the field's natural gas to produce electricity and piping the waste steam to various wellheads for injection. While this eliminates the open flame close to the wellhead, it can involve a large capital expenditure that may become economically viable only when there is a large concentration of wells in a relatively small area. Piping steam to isolated outlying wells is sometimes not viable because too much heat may be lost before the steam gets to the wells. This may cause only distilled water to be delivered to the wellhead.
The chemical solvent method locates a container of solvent near the wellhead, and then injects it down hole with each stroke of the well's pumping unit. While this method eliminates open flames near the wellhead and does not require large capital expenditures, it does add substantial cost to the operation. The chemicals are expensive, costs associated with the transportation and handling of hazardous chemicals is expensive, and the addition of these chemicals to the crude oil makes the refining process more expensive.
Another problem that has become of increasing importance is the treatment and/or disposal of produced water and frac water from oil and gas wells due to the large amounts of water required for hydraulic fracturing and public concerns over drinking water contamination.